<?php
/* 
    Name：FastPHP
    CopyRight: Mr.Fu 2019SR0832915
*/
namespace app\base;
/*
    备份数据库的扩展类
*/
class Backup
{
    private $config=[];
    private $handler;
    private $tables = array();//需要备份的表
    private $begin; //开始时间
    private $error;//错误信息
    public function __construct($config)
    {
        $this->config=$config;
        $this->config['path']=ROOT_PATH .'application'.DS.'data'. DS .'database/'; //默认目录
        $this->config["sqlbakname"]=$this->config["sqlbakname"]??"";
        if ($this->config["sqlbakname"]=="") {
            $this->config["sqlbakname"]=date("YmdHis", time()).".bak";//默认保存文件
        }
        $this->begin = microtime(true);
        header("Content-type: text/html;charset=utf-8");
        $this->connect();
    }
    //首次进行pdo连接
    private function connect()
    {
        try {
            $this->handler =new \PDO(
               "{$this->config['type']}:host={$this->config['hostname']};port={$this->config['hostport']};dbname={$this->config['database']};",
               $this->config['username'],
               $this->config['password'],
               array(
                    \PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES {$this->config['charset']};",
                    \PDO::ATTR_ERRMODE =>  \PDO::ERRMODE_EXCEPTION,
                    \PDO::ATTR_DEFAULT_FETCH_MODE => \PDO::FETCH_ASSOC
                )
           );
        } catch (PDOException $e) {
            echo("Error!: " . $e->getMessage() . "<br/>");
        }
    }
    //查询
    public function query($sql = '')
    {
        $stmt = $this->handler->query($sql);
        $stmt->setFetchMode(\PDO::FETCH_NUM);
        $list = $stmt->fetchAll();
        return $list;
    }
    //获取全部表
    public function get_dbname($dbName = '*')
    {
        $sql = 'SHOW TABLES';
        $list = $this->query($sql);
        $tables = array();
        foreach ($list as $value) {
            $tables[] = $value[0];
        }
        return $tables;
    }
    //获取表定义语句
    public function get_dbhead($table = '')
    {
        $sql = "SHOW CREATE TABLE `{$table}`";
        $ddl = $this->query($sql)[0][1] . ';';
        return $ddl;
    }
    //获取表数据
    public function get_dbdata($table = '')
    {
        $sql = "SHOW COLUMNS FROM `{$table}`";
        $list = $this->query($sql);
        //字段
        $columns = '';
        //需要返回的SQL
        $query = '';
        foreach ($list as $value) {
            $columns .= "`{$value[0]}`,";
        }
        $columns = substr($columns, 0, -1);
        $data = $this->query("SELECT * FROM `{$table}`");
        foreach ($data as $value) {
            $dataSql = '';
            foreach ($value as $v) {
                //开始转义
                $v=addslashes($v);
                $dataSql .= "'{$v}',";
            }
            $dataSql = substr($dataSql, 0, -1);
            $query .= "INSERT INTO `{$table}` ({$columns}) VALUES ({$dataSql});\r";
        }
        return $query;
    }
    //写入文件
    public function writeToFile($tables = array(), $ddl = array(), $data = array())
    {
        $str = "/* FastPHP MySQL Backup Tools \r";
        $str .= "Server:{$this->config['hostname']}:{$this->config['hostport']} \r";
        $str .= "Database:{$this->config['database']} \r";
        $str .= "Data:" . date('Y-m-d H:i:s', time()) . " \r */ \r";
        $str .= "SET FOREIGN_KEY_CHECKS=0; \r";
        $i = 0;
        foreach ($tables as $table) {
            $str .= "-- ----------------------------\r";
            $str .= "-- Table structure for {$table} \r";
            $str .= "-- ---------------------------- \r";
            $str .= "DROP TABLE IF EXISTS `{$table}`; \r";
            $str .= $ddl[$i] . "\r";
            $str .= "-- ---------------------------- \r";
            $str .= "-- Records of {$table} \r";
            $str .= "-- ---------------------------- \r";
            $str .= $data[$i] . "";
            $i++;
        }
        if (!file_exists($this->config['path'])) {
            mkdir($this->config['path']);
        }
        return file_put_contents($this->config['path'].$this->config['sqlbakname'], $str) ? '备份成功!花费时间' . round(microtime(true) - $this->begin, 2) . 'ms' : '备份失败!';
    }
    //设置要备份的表
    public function setTables($tables = array())
    {
        if (!empty($tables) && is_array($tables)) {
            //备份指定表
            $this->tables = $tables;
        } else {
            //备份全部表
            $this->tables = $this->get_dbname();
        }
    }
    //备份
    public function backup($tables = array())
    {
        //存储表定义语句的数组
        $ddl = array();
        //存储数据的数组
        $data = array();
        $this->setTables($tables);
        if (!empty($this->tables)) {
            foreach ($this->tables as $table) {
                $ddl[] = $this->get_dbhead($table);
                $data[] = $this->get_dbdata($table);
            }
            //开始写入
            return $this->writeToFile($this->tables, $ddl, $data);
        } else {
            return '数据库中没有表!';
        }
    }
    public function restore($filename = '')
    {
        $path=$this->config['path'].$filename;

        if (!file_exists($path)) {
            return 'SQL文件不存在!';
        } else {
            $sql = $this->parseSQL($path);
            //dump($sql);die;
            try {
                $this->handler->exec($sql);
                return '还原成功!'.round(microtime(true) - $this->begin, 2) . 'ms';
            } catch (PDOException $e) {
                return $e->getMessage();
            }
        }
    }
    //解析SQL文件为SQL语句数组
    private function parseSQL($path = '')
    {
        $sql = file_get_contents($path);
        $sql = explode("\r", $sql);
        //先消除--注释
        $sql = array_filter($sql, function ($data) {
            if (empty($data) || preg_match('/^-- .*/', $data)) {
                return false;
            } else {
                return true;
            }
        });
        $sql = implode('', $sql);
        //删除/**/注释
        $sql = preg_replace('/\/\*.*\*\//', '', $sql);
        return $sql;
    }
    //下载备份
    public function downloadFile($fileName)
    {
        $fileName=$this->config['path'].$fileName;
        if (file_exists($fileName)) {
            ob_end_clean();
            header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
            header('Content-Description: File Transfer');
            header('Content-Type: application/octet-stream');
            header('Content-Length: ' . filesize($fileName));
            header('Content-Disposition: attachment; filename=' . basename($fileName));
            readfile($fileName);
        } else {
            return "文件有错误！";
        }
    }
    //获取文件时间
    private function getfiletime($file)
    {
        $path=$this->config['path'].$file;
        $a = filemtime($path);
        $time = date("Y-m-d H:i:s", $a);
        return $time;
    }
    //获取文件是大小
    private function getfilesize($file)
    {
        $perms=stat($this->config['path'].$file);
        $size = $perms['size'];
        $a    = ['B', 'KB', 'MB', 'GB', 'TB'];
        $pos  = 0;
        while ($size >= 1024) {
            $size /= 1024;
            $pos++;
        }
        return round($size, 2). $a[$pos];
    }
    
    //获取文件列表
    public function get_filelist($Order = 0)
    {
        $FilePath=$this->config['path'];
        $FilePath = opendir($FilePath);
        $FileAndFolderAyy=array();
        $i=1;
        while (false !== ($filename = readdir($FilePath))) {
            if ($filename!="." && $filename!="..") {
                $i++;
                $FileAndFolderAyy[$i]['name'] = $filename;
                $FileAndFolderAyy[$i]['time'] = $this->getfiletime($filename);
                $FileAndFolderAyy[$i]['size'] = $this->getfilesize($filename);
            }
        }
        $Order == 0 ? sort($FileAndFolderAyy) : rsort($FileAndFolderAyy);
        return $FileAndFolderAyy;
    }
    //删除文件
    public function delfilename($filename)
    {
        $path=$this->config['path'].$filename;
        if (@unlink($path)) {
            return '删除成功';
        }
    }
}
